Math CentralQuandaries & Queries


Question from Pete, a student:

Is the only way to find a cube root of a really big number guess and check, as i read in other questions, or is there another way without a calculator?

Ho Pete,

There are better techniques than guess and check but doing the calculations by hand can be horrendous. Even finding the square root of a large number is numerically intensive. In my response to an earlier question from Tom I show how to use the bisection method to approximate the cube root of 270 and then direct Tom to the Newton-Raphson method which for most problems will reach the required accuracy in fewer steps than the bisection method.


About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS